Professional negligence forms the starting point for a claim, but its assessment alone does not resolve the issue of liability. The dispute requires determining what conduct was reasonably expected, what damage has occurred, and to what extent it can be attributed to the conduct in question. When an insurer is involved, a further issue arises: the actual scope of the cover taken out.
Three recent judgments of the First Chamber allow us to examine these difficulties in particularly relevant areas: healthcare, legal representation and group professional indemnity insurance.
The doctrinal notes accompanying the summaries contain our own critical assessment, distinct from the Court’s reasoning and rulings.
1. Supreme Court Judgment 204/2024, of 19 February: delayed diagnosis and deprivation of a therapeutic opportunity
First Chamber. Appeal 6010/2019. ECLI.ES TS2024:822
Facts and grounds. A patient with transverse myelitis was initially diagnosed with a probable conversion crisis, without adequately ruling out an organic cause. The correct diagnosis and treatment were delayed.
The fourth legal ground identifies the breach of the lex artis as lying in the insufficient use of diagnostic methods and the delay in treatment. It further distinguishes between causation in relation to all sequelae and the deprivation of opportunities for a better outcome: although a cure could not be guaranteed, a legally relevant therapeutic opportunity existed.
The fifth ground specifies the compensation. Taking into account the medical reports, the individual severity of the condition and the possibility of less severe sequelae, it sets the compensation at 33 per cent of the assessed damages. The sixth ground addresses its quantification.
Decision. The Supreme Court upholds the appeal on points of law and awards compensation for the lost opportunity. The percentage corresponds to the proven circumstances; it does not establish a general rule for diagnostic delays.
Doctrinal note: correctly identifying the subject matter of the evidence
In our view, the main significance of this ruling lies in the requirement to specify precisely what is being claimed. To assert that a delay caused all the sequelae requires a different explanation from arguing that it reduced the chances of avoiding them or of lessening their severity.
This distinction must be reflected in the expert evidence. It is insufficient to describe incorrect conduct and then list the injuries. The report should explain what treatment was appropriate, when it should have been administered, what benefit it could reasonably have provided, and how the patient’s particular circumstances influenced the outcome.
It is also advisable to avoid a mechanical use of statistics. The percentages relating to the progression of a disease describe groups; applying them to an individual case requires justification of their comparability. As a criterion for analysis, quantification should demonstrate the link between the medical evidence and the recognised amount, making explicit any remaining uncertainties.
2. Supreme Court Ruling 1681/2025, of 24 November: the failure of an appeal and proof of its prospects of success
First Chamber. Appeal 1277/2020
Facts and grounds. A company claimed compensation from its solicitor for the failure of an appeal. Negligence was not sufficient to prove that the appeal would have yielded a favourable outcome.
The second legal ground rejects the allegations concerning the assessment of evidence and lack of reasoning. It explains that the dismissal of a criminal case for forgery does not prove the authenticity of the disputed signatures. Furthermore, it points out that certain grounds for personal liability had been raised for the first time on appeal: the principles of consistency and preclusion prevented them from being examined.
The third ground identifies a defect in the formulation of the ground for cassation, as it invokes disparate legal provisions together. It adds that the prospects of success of the unsuccessful action had not been sufficiently substantiated, particularly given that those arguments were raised out of time.
Decision. Both extraordinary appeals are dismissed and the refusal to award compensation is upheld.
Doctrinal note: the lost proceedings must be reconstructed within their actual limits
From a doctrinal perspective, the examination of procedural opportunity requires reconstructing the litigation as it could have been legally resolved. Such reconstruction must include both the arguments favourable to the client and the existing evidential and procedural obstacles.
Our assessment is that the claim against the professional loses its merit when it envisages an ‘ideal’ appeal, enriched with arguments that could no longer be incorporated. The opportunity giving rise to compensation must be measured against the proceedings that were actually available.
The ruling also invites a distinction to be drawn between two levels of defence. One consists of denying the professional’s breach; the other, of disputing that such a breach caused the financial loss claimed. Admitting a procedural error does not oblige one to accept the client’s entire assessment of the damage.
For the same reason, the amount of the original claim should be treated with caution: it constitutes a financial benchmark, but requires further analysis of the likelihood of obtaining it.
3. Supreme Court Judgment 83/2026, of 28 January: individual acceptance of the limitations of group insurance. Plenary Session of the First Chamber. Appeal 6830/2020
Facts and grounds. The dispute concerns a time-limited claims-made clause in a group civil liability insurance policy for lawyers.
The third legal ground examines its retrospective nature in accordance with Article 73 of the Insurance Contracts Act. Its restrictive nature determines the application of Article 3: special emphasis and specific acceptance in writing. In group insurance, acceptance by the policyholder body does not replace the information and acceptance requirements applicable to the insured party.
The fourth ground deems the clause null and void and unenforceable due to a lack of individual acceptance and orders the insurer to pay 328,500 euros for one claim and 42,685.05 euros for the other. It further imposes interest in accordance with Article 20: the fact that the claim has been brought before the courts does not, in itself, constitute a justifiable reason for non-payment.
Decision. The appeal is upheld and the claim against the insurer is upheld on the terms set out. The ruling does not declare all claims made clauses invalid.
Doctrinal note: collective insurance contracts require sufficient individual documentation
The practical significance of this issue makes it advisable to examine the insurance policy from the moment it is taken out. For a law firm, a medical practice or any professional organisation, knowing the sum insured provides incomplete information if it is not known when the claim must be made and what time-related conditions have been agreed.
As a preventative measure, individual documentation should be kept that allows the coverage to be reconstructed: applicable conditions, acceptance of the policy, acceptance of restrictions and subsequent amendments. This traceability facilitates both the claim for cover and the assessment of its limits.
From the perspective of the injured party, it is advisable to examine the professional’s liability and the reasons why the insurer is rejecting the claim separately. A dispute regarding the temporal scope of cover may require a different response to one concerning the existence of negligence or the amount of the loss.
Finally, our view is that the early assessment of cover also has an economic dimension: an insufficiently substantiated objection may significantly increase the final cost of the claim.
Conclusions
Firstly. A robust claim must precisely identify the conduct expected and the loss attributed to its breach. The description of the error must be supplemented by a causal explanation.
Second. Loss of opportunity requires specifying which opportunity was lost and what its value was. Its assessment must take account of the individual circumstances and explain the basis for compensation.
Third. In procedural terms, the analysis must respect the pleadings, evidence and limitations that governed the original proceedings. Professional liability proceedings do not permit the retrospective reconstruction of a claim without those constraints.
Fourth. Liability and insurance cover are related issues that require separate examination. The contractual documentation is decisive in assessing the validity of the restrictions invoked.
Fifth. As a practical guide, these judgements advise preparing the case by asking three successive questions: what the professional should have done, what benefit was lost as a result of their actions, and what cover applies to the proven loss.
At Belzuz Abogados S.L.P., as a law firm specialising in Insurance Law and Civil Liability, we are available to advise you on the impact of this reform, both from the perspective of insurance practice and in defending the interests of victims and policyholders.